Samples are printed on print media with at least first and second marking engines. A first lightness value of a solid area of a first sample printed with the first marking engine and a second lightness value of a solid area of a second sample printed with the second marking engine are determined. The first and second solid area lightness values are compared to one another. Based on the comparison, a lighter marking engine and a darker marking engine are identified. Tone reproduction curve of the lighter marking engine is adjusted to substantially match tone reproduction curve of the darker marking engine.